| This story was originally written in 1994. | | | | clues about these earthquakes involves both |
| William Steele, the Seismology Lab Coordinator at | | | | painstaking research and educated guesswork. |
| the University of Washington Geophysics | | | | Research has recently identified a Seattle fault |
| Program, has a son, Chris, who goes to | | | | which generated a large quake between 1,000 to |
| elementary school. "He comes in sometimes and | | | | 1,100 years ago. "There were landslides, and a |
| he loves to do stuff." It seems he'd recently put | | | | huge seiche-when something big falls in the water, |
| a sticker on one of the lab's monitors, and his | | | | creating waves like tsunamis. Large block |
| father had some trouble accessing the equipment. | | | | landslides occurred in forests. Restoration Point on |
| "What an excuse!" Steele never did get into the | | | | Bainbridge Island rose twenty feet from Puget |
| program he'd wanted to show me. | | | | Sound in seconds during that event." |
| December 4th of last year there was a | | | | Buildup from glacial ice sheets once covering the |
| magnitude 5.1 quake in Klamath Falls, Oregon. | | | | continent make it difficult to analyze shallow crust |
| Aftershocks were felt in Washington State. I had | | | | faults. But geologists are pretty sure there are |
| headed out to the UW in search of information on | | | | two major Seattle faults. The biggest one runs |
| recent earthquake activity in the Puget Sound | | | | from the north tip of Mercer Island through |
| region. | | | | Eastgate to the Kingdome, just north of West |
| "Oregon is relatively quiet next to Washington. But | | | | Seattle. The other fault runs through White |
| this year, we've had an enormous amount of | | | | Center, parallel to the bigger one. In 1872, an |
| activity in Oregon, counter to past patterns." | | | | estimated 7.3 shallow quake caused what |
| Klamath Falls couldn't be noisier, said Steele, ticking | | | | seismologists call "felt reports" from observers, |
| off the numbers: September 4th, 5.9; Sept. 20th, | | | | the only evidence of some older quakes. Native |
| 5.9, 5.0, 4.3; Dec. 4th, 5.1; and Christmas Day, 4.0, | | | | Americans tell legends about what must have |
| 3.4. | | | | been some very sizeable earthquakes and |
| Most of our local activity in the Puget Sound | | | | tsunamis. |
| region is recorded by the UW's lab equipment. | | | | Nowadays, all the real-time telemetry (automatic |
| They have an emergency preparation computer | | | | transmission of data from a distant source to a |
| program called "Beat the Quake," hailing from the | | | | receiving station) comes through in the back of |
| land of quakes, California, which has suffered | | | | the lab, where Steele poured me a cup of |
| through quite a lot of severe earthquake damage | | | | Starbucks coffee at their metal sink in a very |
| lately. That's the program Steele had trouble | | | | equipment-crowded space. "Relays 'zap' activity |
| running on his computer. Fortunately, the UW's | | | | energy in nanoseconds to the lab. Before people in |
| Seismology Lab has far more emergency | | | | a region know what's going to hit them, we do." |
| preparedness information "so we don't have to | | | | The helicorders monitor 23 stations on analog. |
| begin from ground zero" in the likely event of an | | | | "We focus on volcanoes. All stations, including the |
| earthquake. Steele is also the Public Information | | | | ones on helicorders, go onto the computer |
| Officer covering quakes through the UW. "We | | | | system in the next room. The discriminator in the |
| have 135 seismic stations throughout Washington | | | | back takes FM carrier signals and separates them |
| and Oregon, currently operating, and we're | | | | from seismic signals, leaving an amplified seismic |
| expanding. We really cover a tremendously broad | | | | signal. It goes to the front room, changing into |
| area." | | | | digital information the computer can read. |
| They locate quakes precisely, then determine the | | | | "If it picks up a 'jump' (a skip in the needle on the |
| magnitude (quantity of total energy released by | | | | helicorder) on a station, it checks other stations |
| the quake), location (area affected by the quake), | | | | and records all data, whether there's a signal or |
| and epicenter (location on the surface directly | | | | not. If it's a big quake, it does estimates of the |
| above the focus, or place where an earthquake | | | | magnitude etc. via programs, beeps the people |
| originates.) | | | | (like Steele), and sends information to |
| They collect data about the geology of the region | | | | seismologists around the region." Steele might |
| as well. "It's critical data. This lab is an educational | | | | hear a "beep" anytime. |
| center for graduate students in geophysics." They | | | | As I drank my coffee, Steele told me he was a |
| also educate citizens. School groups bring in | | | | grad student, his life's partner works, and |
| students, and Steele speaks at civic organizations, | | | | together they support their family, renting a |
| encouraging people to take action and make | | | | house in Wallingford and raising two kids. "It's a |
| themselves safer from earthquakes. | | | | rewarding job, but...the rewards are not |
| Of course, the big question everyone asks is, | | | | monetary." Nonetheless, he feels treated as a |
| "When?" | | | | colleague by everyone, and has a good working |
| "We're not able to put down a date. It's more | | | | relationship with all his "fellows at the lab." |
| complicated because three types of quakes occur | | | | About earthquake preparedness, Steele is |
| in the Puget Sound region. The most common are | | | | adamant. "The secret is not fear and loathing in |
| deep earthquakes. | | | | Seattle, and that we have to hide under our beds. |
| "Signals travel through the planet's crust, | | | | Let's get ready. Our schools need to get to the |
| sometimes all the way from the other side." | | | | point where we can withstand a 7.4 earthquake. |
| Events from anywhere show up on their | | | | How many little bodies do we need under bricks |
| helicorder sheets, making an analog, a 24-hour | | | | before we start spending some money?" Right |
| record, of every quake. For example, the Klamath | | | | now, there are no definite laws enforcing |
| Falls quakes, which are very near California on the | | | | earthquake building codes, "if the building code |
| Oregon coast. | | | | years ago said you could pile bricks without |
| "We cover the Cascade Range, and have multiple | | | | mortar on top of each other." |
| stations on every volcano. We have a good | | | | Unreinforced masonry creates structures that fall |
| station at Mt. Baker, adequate to cover the | | | | during even moderate earthquakes. "The entire |
| region." Earthquakes around volcanoes are very | | | | wall of a school can fall down and kill students. A |
| common. | | | | brick that falls three stories doesn't slow down," |
| The lab shares data with California for quakes | | | | he said, referring to the death of a boy during the |
| occurring on the border of California and Oregon. | | | | 1965 earthquake. Steele is certain such deaths are |
| "We're part of the Washington Regional Seismic | | | | preventable. |
| Network." Steele showed me a map of Pacific | | | | At least six schools in Oregon have unreinforced |
| Northwest Seismicity, 1969-1991. There were | | | | structures, bricks that can fall and fill a doorway, |
| huge blue clusters in Puget Sound. What are | | | | blocking the exit. "Retrofit them, or tear them |
| those, I asked. "Moderate, shallow, and deep | | | | down and build another school. If a school has |
| quakes. The deep clusters are in the Puget Basin." | | | | been considered unsafe for a quake lately, they |
| Deep earthquakes, the ones you really tend to | | | | can sell it, and it becomes a senior center. No laws |
| write home about, are the largest in magnitude as | | | | stop that. These buildings need to be brought up |
| measured on the Modified Mercalli Intensity Scale. | | | | to code or taken down. Deaths will happen unless |
| The values usually range from 1.0 (not felt) to 7.0 | | | | we act. India just had a 6.8 quake...tens of |
| (extreme damage to buildings and land surfaces). | | | | thousands dead. There needs to be water and |
| They can go even higher, as they have in recent | | | | food stored away to last 72 hours. You need to |
| deep quakes in Alaska. | | | | get under a table and ride it out; get down on the |
| Here's what's happening in Puget Sound: about 300 | | | | ground, under something; check to see if you |
| kilometers or more out from the coast is where | | | | smell gas, and turn it off; electricity, too." |
| the deep quakes are generated. There's a ridge | | | | You should get to know your community |
| 500 to 700 kilometers out called the Juan de Fuca | | | | resources, Steele said. And in case of severe |
| Ridge, and new material, new sea floor, is being | | | | aftershocks, if you're in a building "you should wait |
| deposited all the time along it. It pushes the Juan | | | | until the shaking stops, and then get out." Lots of |
| de Fuca plate toward the North American plate | | | | people are killed by falling debris while evacuating |
| underneath the Seattle area. The Juan de Fuca | | | | buildings. |
| plate moves an average of two inches a year, | | | | What does Steele see in the immediate future? "I |
| towards us, lifting the other plate. | | | | expect more of the same. Probably some quakes |
| A border zone locks it up, an interface between | | | | greater than 4.0 in the Puget Sound area. While |
| the two plates that stops the oceanic plate, | | | | we've been talking, there've been events in |
| making it subduct beneath us, forcing the ocean | | | | Klamath Falls,." As I write this, there are |
| plate down into the mantle of the Earth. This | | | | aftershocks east of the Dec. 4 "sequence" |
| boundary is called the Cascadia Subduction Zone, | | | | starting in Klamath Falls. "The question is, are we |
| and extends from the middle of Vancouver Island | | | | going to recognize the danger and do something |
| in British Columbia down to Northern California. | | | | about it, or are we going to wait until we have an |
| The Earth's mantle lies beneath its brittle crust. It's | | | | adequate death toll? I'd like to see a dedicated |
| semi-solid, due to tremendous heat and pressure. | | | | plan and some leadership from the state. It'll be a |
| "Our Cascade volcanoes are probably there | | | | lot of money." |
| because of plate subduction beneath us. The push | | | | Steele said a colleague of his said it best: "The |
| deforms the crust and builds up tremendous | | | | next great disaster will happen as soon as we |
| stresses. Right now, the coast of Washington is | | | | forget about the last one." |
| rising. It's bulging up." The oceanic plate is "cold | | | | What to do other than screaming your lungs |
| rock" and the shock of the two forces meeting | | | | out...fall down! |
| leads to deep earthquakes. Washington has | | | | Apparently, you may hear a very loud, building |
| recently experienced two large ones, in 1949 and | | | | sound before the frenzy begins. The below is |
| 1965. | | | | from "How to Survive in Earthquake Country," a |
| A flyer from the lab states that roughly 1,000 | | | | FEMA pamphlet. Find out about your risks, at |
| earthquakes per year are recorded in Washington | | | | home, and in your workplace. Get more specifics |
| and Oregon. "Between one and two dozen of | | | | from the American Red Cross, or FEMA. |
| these cause enough ground shaking to be felt by | | | | Learn what causes injuries: parts falling off building |
| residents. Most are in the Puget Sound region, and | | | | exteriors and interiors; flying pieces of broken |
| few cause any real damage. However, based on | | | | glass; overturning bookcases; unanchored water |
| the history of past damaging earthquakes and our | | | | heaters; storage facilities; anything made of glass; |
| understanding of the geologic history of the Pacific | | | | fires from damaged gas lines; electric lines; wood |
| Northwest, we are certain that damaging | | | | stoves; chimneys; toxic fumes. |
| earthquakes (magnitude 6.0 or greater) will recur | | | | Create emergency preparedness plans: find safe |
| in our area, although we have no way to predict | | | | spots in your home; identify escape routes; plan |
| whether this is more likely to be today, or years | | | | two ways out of each room; pick two places to |
| from now." Steele thinks it will be soon. | | | | meet, outside your house and outside the |
| "In 1949, there was a severe earthquake in | | | | neighborhood if you can't return home; show |
| Olympia, 7.1. Eight people were killed and there | | | | everyone how to shut off water, gas and |
| was millions of dollars worth of property damage. | | | | electricity; practice your plans, now. |
| The quake was located 70 kilometers deep. | | | | Read "Your Family Disaster Plan," and "Emergency |
| "In 1965, there was a magnitude 6.5 quake | | | | Preparedness Checklist," which you can get from |
| between Seattle and Tacoma." Both earthquakes | | | | FEMA. |
| were felt as far away as Montana. But there | | | | Reduce earthquake hazards: evaluate your home; |
| were no aftershocks, as is usual during a deep | | | | strap water heaters and gas appliances down; |
| quake. The infamous aftershocks, known to catch | | | | remember, stiff items snap; place heavy objects |
| people in the middle of recovering from a bad | | | | on lower shelves; anchor everything heavy; |
| earthquake, happen during land-based shallow | | | | anchor hanging objects; support community |
| earthquakes. The ocean-based shocks occurred | | | | earthquake preparedness. |
| once, causing ground tremors that lasted several | | | | Businesses, schools, daycares, neighborhoods, |
| minutes. "The 1965 quake killed about five people, | | | | churches, clubs: hold workshops. Assemble a |
| and again there was millions of dollars of property | | | | disaster preparedness kit: store food, water, |
| damage." Other deep events, difficult to calculate | | | | clothes, a first aid kit, a radio, flashlights, and |
| from records of the times, occurred in 1882, | | | | batteries, good for 72 hours of use, in your car |
| 1909, and 1939. "Every 35 years or so a 6.0+ | | | | trunk, home, and office. For more details, consult |
| magnitude quake occurs beneath Puget Basin. The | | | | the FEMA brochure, "Your Family Disaster Supplies |
| whole region along the coast will shift at once. | | | | Kit." |
| When it finally builds up enough pressure to kick | | | | During/after an earthquake: stay calm; don't panic |
| up, it'll be a big one." | | | | or run. Earthquakes are usually preceded by loud |
| Eighty percent of the quakes on the planet | | | | sounds, so take quick action. You actually have |
| happen along the Pacific North West Rim, which is | | | | about two seconds, so get ready for that |
| referred to as "The Ring of Fire" because of all | | | | earthquake now to protect yourself and others. |
| our volcanic activity. In 1964, one year before this | | | | Stay where you are: drop, cover and hold |
| area's last big event, south-central Alaska | | | | something solid, or take immediate cover under a |
| generated a monster 9.3 quake, shaking the | | | | heavy desk or table, in a doorway, hallway, or |
| ground for twenty minutes, generating tidal | | | | against inside walls. Turn away from glass. Keep |
| waves that decimated Seward's coast, affected | | | | away from chimneys, windows, tall bookcases, |
| 34,000 square miles, and killed 143 people. And | | | | and objects that might fall. |
| there's been recent large quakes in Cape | | | | Evacuate only after the shaking stops. Use the |
| Mendecino, California, and Parkfield, California, | | | | stairs, not the elevator. Remember, aftershocks |
| infamous for ground shaking, in 1992. | | | | may occur at any time. Listen to a radio or TV |
| Brian Atwater of the USGS (United States | | | | for instructions. Outdoors: move away from |
| Geological Service) and the UW geology | | | | buildings, trees, and utility wires. Sit on the ground |
| department has done studies along the coasts of | | | | until the shaking stops. Flee inland immediately |
| Washington and Oregon. He's found a kind of | | | | when near a coastline. Check for injuries. Do not |
| layered soil..."what he found...ghost forests killed by | | | | move seriously injured people unless they're in |
| the last big quakes. Subduction zone material | | | | danger. Indoors: evacuate damaged buildings, as |
| covered by coarse black sand." A layer gradually | | | | aftershocks could cause additional damage, or |
| turned into forest floor and then the sand layer. | | | | buildings can collapse. |
| "As bulging continues, coastline rises, and low-lying | | | | Do not re-enter a building until it's declared safe |
| areas are flushed clean by salt water. Stress | | | | by responsible authorities. Don't use the telephone |
| released during the quake makes the coastline | | | | except for emergencies; stay off the phone. |
| subside by seven or eight feet. It 'drops.' If you're | | | | Check for fires. Have a fire extinguisher, and |
| living at five feet above sea level, it's not a very | | | | know how to use it. Check utilities: gas, electric, |
| comfortable thing." | | | | and water lines may be broken. Gas: do not use |
| Earthquakes also generate large tsunamis, or tidal | | | | matches, candles, open flames or electric |
| waves; the biggest ones, generated by larger | | | | switches indoors, because of possible gas leaks. If |
| quakes, can rip up an entire coastline for miles, | | | | you smell gas, open windows, leave, and shut off |
| wiping out bridges, roads, and buildings. The really | | | | the main gas valve, which is usually outside. |
| great subduction zone quakes, 9.0 or more, only | | | | Electricity: if wiring is broken, shut off electricity at |
| occur about once a century on the face of the | | | | the main switch. Don't touch anything near |
| planet. Strangely, a big quake may result in only | | | | downed or damaged lines. Water: if water pipes |
| about three-and-a-half minutes worth of strong | | | | are broken, shut off the supply at the main valve |
| ground shaking, which doesn't sound like much. | | | | outside. Use water from ice cubes, water heaters, |
| "One recent California quake was only seventeen | | | | toilet tanks (if they don't contain chemical |
| seconds of strong ground motion, a 7.1 quake. A | | | | cleaners). Clean up spills. Attend carefully to spills |
| 7.0 quake releases the equivalent of 199,000 tons | | | | of potentially harmful materials such as medicines, |
| of TNT in energy; a 9.0 releases 200 million tons, | | | | drugs, and household cleaners. Provide adequate |
| or 17,000 atomic bombs' worth of force. | | | | ventilation, as chemicals may combine to produce |
| "The difference between an 8 and a 9 is greater | | | | toxic gas. Remember to assist others in need. |
| than the difference between a 2 and an 8, | | | | Finally, please remember to keep current on the |
| because of the logarithmic scale. The force | | | | "stats" regarding earthquakes, volcanoes and |
| increases exponentially. It gets 30 times greater | | | | other natural disasters in your area, so you have |
| each time." I wondered if it ever goes up to 10.0. | | | | a pretty good idea what to do - in the likely |
| By carbon-14 dating organic matter in ground and | | | | event you will have to suffer through one. And |
| sea levels, "scientists can determine approximate | | | | also remember: it's not your fault. (Sorry about |
| dates for events going back 10,000 years." Finding | | | | that, I couldn't resist the joke. |